One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,6,8)(3,7,5,4)(10,14)(11,12)(19,23)(21,24)(26,30)(28,35)(31,36)(34,39)(1,3,6,5)(2,4,8,7)(9,10,13,14)(11,16,12,15)(17,18,20,22)(19,21,23,24)(26,30)(27,33)(32,37)(34,39)(1,4)(2,5)(3,8)(6,7)(9,11,13,12)(10,15,14,16)(25,26)(27,31)(28,32)(29,30)(33,36)(34,38)(35,37)(39,40)(1,4)(2,3)(5,8)(6,7)(9,10)(11,15)(12,16)(13,14)(17,19)(18,21)(20,23)(22,24)(25,27)(26,31)(28,34)(29,33)(30,36)(32,38)(35,39)(37,40) involution — undirected(1,5,6,3)(2,7,8,4)(9,12,13,11)(10,15,14,16)(25,28,29,35)(26,32,30,37)(27,34,33,39)(31,38,36,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.